Estimate rolls needed for a room or feature wall — with roll size, pattern repeat, doors/windows, waste and cost.
Total wall width = perimeter = 2 × (length + width).
Openings (optional)
Openings reduce area, but wallpaper is hung as full vertical drops — a small opening often doesn't reduce the roll count, since the offcut above/below it usually can't be reused elsewhere. This calculator notes that limitation rather than assuming a precise roll saving.
Wallpaper Roll
Enter the roll width and length printed on your specific product label — roll sizes genuinely vary between manufacturers and regions, so there's no single figure this calculator should assume for you.
Pattern
Waste & Cost
Trimming allowance and pattern-repeat length are already built into the drop calculation above — contingency waste is a separate, additional margin for mistakes, offcuts and future repairs, applied to the roll count itself.
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Written and reviewed by Mohsin Iqbal · Last reviewed August 2026
A wallpaper calculator works out how many rolls you need from your room or wall measurements, your roll's actual size, and how the pattern repeats — going well beyond a simple area-versus-roll-area division, which understates real requirements once you account for how wallpaper is actually cut and hung.
It depends on your wall area, your specific roll's width and length, and whether the pattern needs to match between strips. For a straightforward room with no pattern repeat, a rough guide is one roll per 5–5.5 m² of wall — but this varies by roll size, and pattern matching can meaningfully increase that. Enter your actual measurements above for a figure specific to your project.
Measure room length and width for the whole-room mode (perimeter is calculated automatically), or a single wall's width for a feature wall. Measure wall height from floor to ceiling. For doors and windows, measure each opening's width and height — if you have several of the same size, enter the quantity rather than adding rows one at a time.
There is no single universal wallpaper roll size — roll width and length genuinely vary between manufacturers and regions. Always use the roll width and length printed on your actual product label rather than assuming a standard figure; this calculator's roll fields are fully editable for exactly that reason.
Divide the number of drops needed by the number of full drops you can cut from one roll, then round up to the next whole roll. Drops needed is total wall width divided by roll width, rounded up. Drops per roll is roll length divided by the adjusted drop length (wall height, plus trim, plus any pattern-repeat rounding), rounded down. Rolls required is drops needed divided by drops per roll, always rounded up to a whole roll — you can never buy 8.8 rolls.
Pattern repeat is the vertical distance before a design repeats itself — printed on the roll label, commonly anywhere from a few centimetres to over half a metre for large motifs. A repeat of 0 means plain or free-match wallpaper with no pattern to align.
This is where a naive wall-area-divided-by-roll-area calculation goes wrong. With a pattern repeat, each drop must be cut to a length that's a whole multiple of the repeat — not just wall height plus a flat allowance — so consecutive drops stay in phase with each other as you work along the roll. That rounding-up step, not the repeat length itself, is what typically pushes usage higher.
Adjusted drop length = ceil((Wall height + Trim) ÷ Pattern repeat) × Pattern repeat
For random or free-match wallpaper, no such rounding applies — the drop length is simply wall height plus trim allowance, since there's no pattern to keep in phase.
A "drop" (or strip) is one full-height cut length of wallpaper, hung as a single vertical piece. The number of drops needed is your total wall width divided by roll width, rounded up — you can't hang a fraction of a drop, so any partial drop still needs a full one cut for it.
Roll width and length vary by manufacturer, product line and sometimes country — there's no figure this calculator should assume on your behalf. Check the label on your specific roll for its exact printed dimensions before ordering.
Some wallpaper, particularly in North America, is sold in "double rolls" — a single physical roll containing twice the length of a traditional single roll, priced and often quoted in coverage as one double-roll unit. Check your specific product's packaging to see which convention it uses, and enter the actual roll length printed on the label into this calculator rather than assuming single or double.
This calculator shows the area doors and windows remove from the gross wall total, for reference. It does not reduce the roll count based on openings alone — wallpaper is installed as full vertical drops, and the offcut above or below a door or window usually can't be reused on another wall, so a small opening often doesn't actually save you a roll even though it reduces the raw area.
Beyond the trim allowance and pattern-repeat rounding already built into the drop calculation, a separate contingency margin (commonly 10%) is worth adding for installation mistakes, future repairs and matching offcuts. Buying an extra roll from the same batch/dye lot is also worth considering, since colour can vary slightly between production runs and a later top-up order may not match.
Trimming allowance, pattern-repeat rounding, and contingency waste are three genuinely different things — this calculator keeps them separate rather than double-counting. Trim allowance (commonly around 10cm total) covers the excess cut off at ceiling and skirting board on every drop. Pattern-repeat rounding is the ceiling-to-repeat-multiple step above, built into the drop length itself. Contingency waste is a separate percentage applied to the final roll count, for everything else.
A single feature or accent wall uses the same drop-based calculation as a whole room, just with one wall's width instead of a full perimeter — select Feature Wall mode and enter that wall's width and height.
Enter a price per roll to see estimated total cost, based on the recommended (waste-inclusive) roll count. The currency selector is a display label only — it doesn't perform exchange-rate conversion, so enter your price in whichever currency you're actually paying.
Room, wall, door and window dimensions can be entered in metres, centimetres, millimetres, feet or inches, converted internally so you don't need to convert by hand. Roll width stays in centimetres regardless of your chosen unit, since that's how it's virtually always printed on the product label internationally, even on rolls sold in imperial-measuring countries.
| Step | Working | Result |
|---|---|---|
| Gross wall area | 4m × 2.4m | 9.60 m² |
| Adjusted drop length | 2.4m + 0.10m trim | 2.500 m |
| Drops needed | ceil(4m ÷ 0.53m) | 8 |
| Drops per roll | floor(10m ÷ 2.5m) | 4 |
| Minimum rolls | ceil(8 ÷ 4) | 2 |
| With 10% contingency | ceil(2 × 1.10) | 3 rolls |
Perimeter 15.00m, gross wall area 36.00 m². Door (0.8m×2.0m) and two windows (1.2m×1.2m each) total 4.48 m² deducted for reference (net area 31.52 m²) — but since drops are still calculated from the full perimeter, the roll count uses all 29 drops needed, giving 9 rolls with 10% contingency.
Same 4m × 3.5m room, but now with a 64cm pattern repeat: adjusted drop length rounds up from 2.500m to 2.560m (the next whole multiple of 64cm above wall height + trim), which drops the fit from 4 drops per roll down to 3. Same 29 drops needed, but now 11 rolls required — two more than the same room without a pattern repeat, purely from the repeat's rounding effect.
A tool that works out how many wallpaper rolls you need from your room or wall measurements, your roll's actual width and length, and pattern repeat — going beyond a simple area-versus-roll-area estimate.
It depends on your wall area, roll size and pattern repeat. Enter your specific measurements above rather than relying on a general rule, since roll sizes and pattern repeat both genuinely change the answer.
Divide the number of drops your wall needs by how many drops fit on one roll, then round up to a whole roll. This calculator does that automatically from your wall and roll dimensions.
Measure room length and width for whole-room mode, or a single wall's width for a feature wall, plus wall height. Measure any doors or windows you want to account for separately.
Work out drops needed (wall width ÷ roll width, rounded up) and drops per roll (roll length ÷ adjusted drop length, rounded down), then divide drops needed by drops per roll and round up to a whole roll.
Roll width × roll length gives the nominal area, but actual usable coverage is usually less once drops, trimming and pattern matching are accounted for — a roll's real yield depends on your specific wall height and pattern repeat, not just its raw area.
It varies by manufacturer and region — there's no single standard size. Always check the width and length printed on your specific product's label and enter those exact figures.
The vertical distance before a printed design repeats itself, found on the roll label. A repeat of 0 means plain or random/free-match wallpaper with nothing to align between strips.
Often, yes — because each drop must be cut to a whole multiple of the repeat to keep consecutive strips in phase, which can reduce how many drops fit on a roll. In a worked example on this page, adding a 64cm repeat increased a room from 9 to 11 rolls.
Add your trim allowance to wall height, then round up to the next whole multiple of the pattern repeat: adjusted drop length = ceil((height + trim) ÷ repeat) × repeat. This calculator does this automatically once you select straight or drop match and enter a repeat.
Roll length divided by the adjusted drop length, rounded down to a whole number — you can only count complete drops, since a partial drop isn't usable.
This calculator shows the area they remove for reference, but doesn't reduce the roll count based on openings alone — wallpaper is hung as full vertical drops, and offcuts from around a door or window usually can't be reused elsewhere.
Beyond the trim and pattern-repeat allowances already built into the drop calculation, a contingency margin of around 10% is a reasonable starting point for mistakes and future repairs — adjust based on your own confidence and the complexity of the room.
A double roll (common in North America) contains twice the length of a single roll in one physical unit. Always use the actual roll length printed on your product's label rather than assuming which convention it uses.
A pattern that lines up horizontally straight across from one strip to the next, at the same height. It requires the pattern-repeat rounding described above when calculating drop length.
Also called half-drop match — the pattern offsets vertically between adjacent strips rather than lining up straight across. This calculator uses the same drop-length formula as straight match, but half-drop layouts often waste more material in practice than that estimate reflects, since offset strips can't always maximise drops per roll.
Yes — the drop and roll-count math is the same regardless of adhesive type. Enter the roll dimensions and pattern repeat from your specific peel-and-stick product's label.
Yes — select metres, centimetres or millimetres from the unit selector for room, wall, door and window dimensions.
Yes — select feet or inches from the unit selector. Roll width stays in centimetres regardless, since that's how it's virtually always printed on the label internationally.
Select Feature Wall mode and enter that single wall's width and height, rather than a full room perimeter.
Enter a price per roll — the calculator multiplies it by the recommended (waste-inclusive) roll count for an estimated total, using your chosen currency as a display label only.